The U.S. Supreme Court has agreed to hear a long-running First Amendment case that may decide whether public schools have the authority to discipline students for their off-campus, online speech. The case in question stems from a 2017 incident in which a Pennsylvania high school student, identified as B.L., posted a profanity-loaded message on the social media platform Snapchat after she was placed on the junior varsity cheerleading team instead of the varsity team. A teammate of B.L. took a screenshot of her offensive message and reported it to cheerleading coaches, who then suspended the teenager from the team for a year, citing team and school rules about foul language and disrespect for teammates and coaches. B.L., represented by the Pennsylvania chapter of the American Civil Liberties Union, sued the school district, alleging that the punishment violated her freedom of speech. A federal district court judge ordered the school to …